Liquid ejecting head, liquid ejecting apparatus, flow path structure, and method of manufacturing liquid ejecting head

ABSTRACT

A liquid ejecting head including a nozzle configured to eject a liquid, a liquid flow path communicating with the nozzle, a communication chamber including a communication port configured to communicate with atmospheric air, a partitioning wall portion provided between the liquid flow path and the communication chamber, the partitioning wall portion including an opening portion that communicates the liquid flow path and the communication chamber to each other, and an elastic member closing the opening portion.

The present application is based on, and claims priority from JPApplication Serial Number 2019-116436, filed Jun. 24, 2019, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a liquid ejecting head, a liquidejecting apparatus, a flow path structure, and a method of manufacturinga liquid ejecting head.

2. Related Art

Hitherto, a technique for ejecting a liquid on a medium such as printingpaper through nozzles has been proposed. For example, JP-A-63-5947discloses an ink jet head in which a passage for cleaning (hereinafter,referred to as a “cleaning passage”) is formed in a wall surface of anink passage in communication with nozzles. The cleaning passage extendsfrom the ink passage to an opening formed in an exterior surface of ahead body. Insides of the nozzles are cleaned by having the cleaningsolution flow through the cleaning passage. When the cleaning iscompleted, the opening formed in the exterior surface of the head bodyis closed by a closing member.

In the technique in JP-A-63-5947, at the stage after cleaning, in whichthe opening of the cleaning passage has been closed by the closingmember, air resides in the cleaning passage. Furthermore, due to theflow of the cleaning solution, the dust moved from inside the nozzlesmay reside in the cleaning passage. In the technique in JP-A-63-5947,the state in which the nozzles are in communication with the cleaningpassage is maintained even at the stage when the ink jet head is used.Accordingly, foreign matters such as air bubbles, dust, and the likeresiding in the cleaning passage moving near the nozzles may cause aliquid ejection failure.

SUMMARY

In order to overcome the above issue, a liquid ejecting head accordingto an aspect includes a nozzle that ejects a liquid, a liquid flow pathin communication with the nozzle, a communication chamber including acommunication port configured to communicate with atmospheric air, apartitioning wall portion provided between the liquid flow path and thecommunication chamber, the partitioning wall portion including anopening portion that communicates the liquid flow path and thecommunication chamber to each other, and an elastic member that closesthe opening portion.

A flow path structure according to an aspect includes a liquid flow pathin communication with a nozzle that ejects a liquid, a communicationchamber configured to communicate with atmospheric air, a partitioningwall portion provided between the liquid flow path and the communicationchamber, the partitioning wall portion including an opening portion thatcommunicates the liquid flow path and the communication chamber to eachother, and an elastic member that closes the opening portion.

A method of manufacturing a liquid ejecting head according to an aspect,in which the ejecting head includes a nozzle that ejects a liquid, aliquid flow path in communication with the nozzle, a communicationchamber including a communication port configured to communicate withatmospheric air, a partitioning wall portion provided between the liquidflow path and the communication chamber, the partitioning wall portionincluding an opening portion that communicates the liquid flow path andthe communication chamber to each other, and an elastic memberaccommodated in the communication chamber, the method of manufacturingthe liquid ejecting head including cleaning the nozzle and the liquidflow path by supplying a cleaning solution to the communication chamberthrough the nozzle, the liquid flow path, and the opening portion and bydischarging the cleaning solution through the communication port, andpress-fitting the elastic member in the opening portion by supplying agas to the communication chamber through the communication port.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a liquid ejecting apparatusaccording to a first exemplary embodiment.

FIG. 2 is a cross-sectional view of a liquid ejecting head.

FIG. 3 is an exploded perspective view of a liquid ejecting unit.

FIG. 4 is a cross-sectional view in which a vicinity of a communicationchamber has been enlarged.

FIG. 5 is a cross-sectional view focused on an opening portion.

FIG. 6 is a trihedral figure illustrating, as an example, aconfiguration of a blocking member.

FIG. 7 is a schematic diagram illustrating a state in which the elasticmember has been separated from the shaft member.

FIG. 8 is an explanatory drawing of a cleaning process of the liquidejecting head.

FIG. 9 is a schematic diagram of the elastic member in the cleaningprocess.

FIG. 10 is an enlarged cross-sectional view of a vicinity of acommunication chamber according to a second exemplary embodiment.

FIG. 11 is a side view of an elastic member according to the secondexemplary embodiment.

FIG. 12 is an enlarged cross-sectional view of a vicinity of acommunication chamber according to a third exemplary embodiment.

FIG. 13 is a cross-sectional view of an elastic member according to athird exemplary embodiment.

FIG. 14 is a perspective view of a portion of a shaft member accordingto a fourth exemplary embodiment.

FIG. 15 is a cross-sectional view of a liquid ejecting head according toa fifth exemplary embodiment.

FIG. 16 is a side view of a blocking member according to a modification.

FIG. 17 is an enlarged cross-sectional view of a vicinity of acommunication chamber according to a modification.

FIG. 18 is a side view of a blocking member according to a modification.

FIG. 19 is an enlarged cross-sectional view of a vicinity of acommunication chamber according to a modification.

FIG. 20 is an explanatory drawing of a process in which an elasticmember according to a modification is inserted into an opening portion.

FIG. 21 is an enlarged cross-sectional view of a vicinity of acommunication chamber according to a modification.

DESCRIPTION OF EXEMPLARY EMBODIMENTS First Exemplary Embodiment

FIG. 1 is a block diagram of a portion of a liquid ejecting apparatus100 according to a first exemplary embodiment. The liquid ejectingapparatus 100 of the first exemplary embodiment is an ink jet printingapparatus that ejects droplets of ink, which is an example of a liquid,on a medium 11. The medium 11 is printing paper, for example. However,an object to be printed formed of any material, such as a resin film orfabric, may be used as the medium 11. The liquid ejecting apparatus 100is provided with a liquid container 12. The liquid container 12 storesthe ink. For example, a cartridge configured to detach from the liquidejecting apparatus 100, a bag-shaped ink pack formed of flexible film,or an ink tank into which ink can be refilled is used as the liquidcontainer 12. Note that any number and any type of ink can be stored inthe liquid container 12.

As illustrated as an example in FIG. 1, the liquid ejecting apparatus100 includes a control unit 21, a transport mechanism 22, a movingmechanism 23, and a liquid ejecting head 24. The control unit 21including a processing circuit such as a central processing unit (CPU)or a field programmable gate array (FPGA) and a memory circuit such as asemiconductor memory control each element of the liquid ejectingapparatus 100.

The transport mechanism 22 transports the medium 11 along a Y-axis underthe control of the control unit 21. The moving mechanism 23 reciprocatesthe liquid ejecting head 24 along an X-axis under the control of thecontrol unit 21. The X-axis and the Y-axis are orthogonal to each other.The moving mechanism 23 of the first exemplary embodiment includes asubstantially box-shaped transport body 231 that houses the liquidejecting head 24, and an endless belt 232 to which the transport body231 is fixed. Note that a configuration in which a plurality of liquidejecting heads 24 are mounted in the transport body 231 or aconfiguration in which the liquid container 12 is mounted in thetransport body 231 together with the liquid ejecting head 24 can beadopted.

The liquid ejecting head 24 ejects ink, which is supplied from theliquid container 12, to the medium 11 through a plurality of nozzlesunder the control of the control unit 21. Concurrently with thetransportation of the medium 11 performed by the transport mechanism 22and the repetitive reciprocation of the transport body 231, the liquidejecting head 24 ejects ink onto the medium 11 to form an image on asurface of the medium 11.

The liquid ejecting head 24 includes a flow path structure 30 and aliquid ejecting unit 40. The flow path structure 30 is a structure inwhich a flow path that supplies the ink, which has been supplied fromthe liquid container 12, to the liquid ejecting unit 40 is formed. Theliquid ejecting unit 40 ejects the ink supplied from the flow pathstructure 30 through each of the plurality of nozzles.

FIG. 2 is a cross-sectional view of the liquid ejecting head 24. FIG. 3is an exploded perspective view of the liquid ejecting unit 40. Thecross section of the liquid ejecting unit 40 illustrated in FIG. 2corresponds to a cross section taken long line II-II in FIG. 3. Notethat a Z-axis orthogonal to a XY plane is assumed in the followingdescription. The direction in which the Z-axis extends corresponds to avertical direction.

As illustrated as an example in FIG. 3, the liquid ejecting unit 40includes a plurality of nozzles N arranged along the Y-axis. Theplurality of nozzles N are divided into a first nozzle line L1 and asecond nozzle line L2 that are parallelly arranged with a gap inbetween. The first nozzle line L1 and the second nozzle line L2 are eacha collection of the plurality of nozzles N arranged in a straight linealong the Y-axis. As it can be understood from FIG. 2, the liquidejecting unit 40 of the first exemplary embodiment is structured so thatthe elements related to each of the nozzles N of the first nozzle lineL1 and the elements related to each of the nozzles N of the secondnozzle line L2 are provided in substantially plane-symmetric manner witha reference plane O, which is a plane parallel to the YZ plane, inbetween. Accordingly, in the following description, the elementscorresponding to the first nozzle line L1 will be described extensivelyand a description of the elements corresponding to the second nozzleline L2 will be omitted as appropriate.

As illustrated as an example in FIGS. 2 and 3, the liquid ejecting unit40 of the first exemplary embodiment includes a first substrate 41, asecond substrate 42, a diaphragm 43, a plurality of piezoelectricelements 44, a sealing plate 45, a housing portion 46, a nozzle plate47, and compliance portions 48. The second substrate 42, the diaphragm43, the plurality of piezoelectric elements 44, the sealing plate 45,and the housing portion 46 are provided in a Z-axis negative directionwith respect to the first substrate 41, and the nozzle plate 47 and thecompliance portions 48 are provided in a Z-axis positive direction withrespect to the first substrate 41. The nozzle plate 47 is a plate-shapedmember in which the plurality of nozzles N constituting the first nozzleline L1 and the second nozzle line L2 are formed.

As illustrated as an example in FIGS. 2 and 3, first spaces 411, aplurality of first supply paths 412, a plurality of second supply paths413, and relay flow paths 414 are formed in the first substrate 41. Eachfirst space 411 is an opening elongated along the Y-axis. Each firstsupply path 412 and each second supply path 413 are through holes formedfor a corresponding nozzle N. Each relay flow path 414 is a space formedso as to be elongated along the Y-axis and across a plurality of nozzlesN. Each relay flow path 414 communicates the corresponding first spaces411 and the corresponding plurality of first supply paths 412 to eachother. Each of the plurality of second supply paths 413 overlaps asingle nozzle N corresponding to the relevant second supply path 413 inplan view.

As illustrated as an example in FIGS. 2 and 3, a plurality of pressurechambers C are formed in the second substrate 42. A pressure chamber Cis formed for each nozzle N and is a space elongated along the X-axis inplan view. The plurality of pressure chambers C are arranged along theY-axis.

As illustrated as an example in FIG. 3, the diaphragm 43, which iselastically deformable, is provided on a surface of the second substrate42 on the side opposite the first substrate 41. When in plan view in theZ-axis direction, the diaphragm 43 is a plate-shaped member formed in arectcorner shape elongated along the Y-axis. As understood from FIGS. 2and 3, the pressure chambers C are spaces positioned between the firstsubstrate 41 and the diaphragm 43. As illustrated as an example in FIG.2, each pressure chamber C is in communication with the correspondingfirst supply path 412 and the corresponding second supply path 413.Accordingly, each pressure chamber C is in communication with acorresponding one of liquid storage chambers R through the correspondingfirst supply path 412 and the corresponding relay flow path 414, and isin communication with the corresponding nozzle N through thecorresponding second supply path 413.

As illustrated as an example in FIGS. 2 and 3, the piezoelectricelements 44, each for a corresponding pressure chamber C, are formed ona surface of the diaphragm 43 in the Z-axis negative direction. Thepiezoelectric elements 44 are drive elements each elongated along theX-axis in plan view. A plurality of piezoelectric elements 44 arearranged along the Y-axis. Each piezoelectric element 44 changes thepressure in the corresponding pressure chamber C by being deformedaccording to a voltage applied thereto. By having the piezoelectricelement 44 change the pressure inside the pressure chamber C, the inkinside the pressure chamber C is ejected from the nozzle N. The sealingplate 45 is a structure that protects the plurality of piezoelectricelements 44 and that reinforces the mechanical strength of the secondsubstrate 42 and the diaphragm 43. The sealing plate 43 is fixed to thesurface of the diaphragm with an adhesive agent, for example. Note thatthe pressure chambers C may be formed by selectively removing portionsof the second substrate 42 in a thickness direction by etching, forexample. In other words, the second substrate 42 and the diaphragm 43may be formed integrally. Furthermore, instead of the piezoelectricelements 44, heating elements can be employed as the drive elements.

The housing portion 46 in FIG. 3 is a case that stores the ink suppliedto the plurality of pressure chambers C and is, for example, formed of aresin material by injection molding. As illustrated as an example inFIG. 2, supply ports 461 and second spaces 462 are formed in the housingportion 46. Each supply port 461 is a pipe line through which the ink issupplied from the flow path structure 30, and is in communication withthe corresponding second space 462. As illustrated in FIG. 2, each firstspace 411 of the first substrate 41 and the corresponding second space462 of the housing portion 46 are in communication with each other.Spaces configured of the first spaces 411 and the second spaces 462function as the liquid storage chambers R that store the ink supplied tothe plurality of pressure chambers C. The ink supplied from the flowpath structure 30 and that has passed through the supply ports 461 isstored in the liquid storage chambers R. The ink stored in the liquidstorage chamber R is branched from the relay flow path 414 to the firstsupply path 412 and is supplied and filled into the plurality ofpressure chambers C in a parallel manner. The compliance portions 48 areflexible films constituting wall surfaces of the liquid storage chambersR and absorb the pressure fluctuations of the ink inside the liquidstorage chambers R.

As illustrated as an example in FIG. 2, a flow path including a supplyflow path 31, a stored liquid chamber 32, a liquid flow path 33, acommunication chamber 34, and a communication flow path 35 is formedinside the flow path structure 30. An introduction port 36, dischargeports 37, and a release port 38 are formed in outer wall surfaces of theflow path structure 30. Two discharge ports 37 corresponding to thefirst nozzle line L1 and the second nozzle line L2 are formed in theflow path structure 30 of the first exemplary embodiment. For example,the flow path structure 30 is configured of layers of a plurality ofsubstrates, and the inner flow path of the flow path structure 30 isformed by the recessed portions formed in the surface of each substrate.Note that a valve mechanism that controls the flow of the ink may beprovided inside the flow path structure 30. For example, a control valvethat controls the pressure of the ink, or an on-off valve thatopens/closes the ink flow path may be provided inside the flow pathstructure 30.

The supply flow path 31 is a flow path that communicates theintroduction port 36 and the stored liquid chamber 32 to each other. Theintroduction port 36 is an opening through which the ink is suppliedfrom the liquid container 12. A filter 321 that collects foreign matters(air bubbles or dust, for example) mixed in the ink is provided in thestored liquid chamber 32. In other words, numerous fine through holesthat allow the ink to pass therethrough but block foreign matters frompassing therethrough are formed in the filter 321. Note that the innerdiameters of the through holes in the filter 321 in the first exemplaryembodiment are set equivalent to or smaller than the inner diameter ofthe nozzle N.

The liquid flow path 33 is a flow path that communicates the storedliquid chamber 32 and the discharge ports 37 to each other. Eachdischarge port 37 is an opening that is in communication with thecorresponding supply port 461 of the liquid ejecting unit 40. Asunderstood from the above description, the ink supplied to theintroduction port 36 from the liquid container 12 passes through thesupply flow path 31, the stored liquid chamber 32, the liquid flow path33, and each discharge port 37, and is supplied to each liquid storagechambers R through the corresponding supply port 461 of the liquidejecting unit 40. As described above, each liquid storage chamber R isin communication with the corresponding nozzles N. Accordingly, theliquid flow path 33 corresponds to a flow path that is in communicationwith a plurality of nozzles N. Specifically, the liquid flow path 33 isa flow path that supplies the ink, which has passed through the filter321 inside the stored liquid chamber 32, to the nozzles N.

The communication chamber 34 is a space in communication with the liquidflow path 33. A cross-sectional shape of the communication chamber 34 ina cross section perpendicular to the Z-axis is circular, for example.The communication flow path 35 is a flow path that communicates thecommunication chamber 34 and the release port 38 to each other. Therelease port 38 is an opening in communication with the atmospheric air.In other words, the communication chamber 34 is in communication withthe atmospheric air through the communication flow path 35 and therelease port 38. In a state in which the liquid ejecting head 24 is inan actually operating state (hereinafter, referred to as an “operatingstate”), the release port 38 is closed with a closing member 381. Notethat the closing member 381 may be omitted.

The communication flow path 35 of the first exemplary embodimentincludes a first flow path 351, a second flow path 352, and a third flowpath 353. The first flow path 351 communicates the communication chamber34 and the second flow path 352 to each other. The third flow path 353communicates the second flow path 352 and the release port 38 to eachother. The first flow path 351 and the third flow path 353 both extendalong the Z-axis. On the other hand, the second flow path 352 extends ina direction intersecting the Z-axis. For example, the second flow path352 extends in a direction parallel to the XY plane. As understood fromthe above description, the communication flow path 35 includes portionsthat extend along the Z-axis (in other words, the first flow path 351and the third flow path 353) and a portion that extends in the directionintersecting the Z-axis (in other words, the second flow path 352).

FIG. 4 is a cross-sectional view in which a vicinity of thecommunication chamber 34 has been enlarged. As illustrated as an examplein FIG. 4, a communication port 341 is formed in the communicationchamber 34. The communication port 341 is an opening formed in an uppersurface of the communication chamber 34 and is in communication with thecommunication flow path 35. In other words, the communication port 341is an opening that is configured to communicate with the atmosphericair.

As illustrated as an example in FIG. 4, a partitioning wall portion 51is provided between the liquid flow path 33 and the communicationchamber 34. The partitioning wall portion 51 is a wall-shaped portionthat partitions the liquid flow path 33 and the communication chamber 34from each other. As illustrated as an example in FIG. 4, thepartitioning wall portion 51 includes a first face Fa1 and a second faceFa2. The first face Fa1 is a flat surface that opposes the liquid flowpath 33. The second face Fa2 is a flat surface that opposes thecommunication chamber 34. In other words, the first face Fa1 is an areathat constitutes a portion of an inner wall surface of the liquid flowpath 33. In other words, the second face Fa2 is an area that constitutesa portion of an inner wall surface of the communication chamber 34.Specifically, in the communication chamber 34, the second face Fa2constitutes a bottom surface that opposes an upper surface in which thecommunication port 341 is formed.

An opening portion 52 that communicates the liquid flow path 33 and thecommunication chamber 34 to each other is formed in the partitioningwall portion 51. In other words, the partitioning wall portion 51includes the opening portion 52. In other words, the partitioning wallportion 51 defines the opening portion 52. Specifically, the openingportion 52 is a circular opening that penetrates the partitioning wallportion 51 along the Z-axis from the first face Fa1 to the second faceFa2. In other words, the opening portion 52 is a space branched off fromthe liquid flow path 33. Specifically, the opening portion 52 branchesoff from a point between the filter 321 and the nozzle N in the liquidflow path 33. In other words, the Z-axis is a central axis of theopening portion 52. In other words, the central axis of the openingportion 52 extends along the vertical direction.

FIG. 5 is a cross-sectional view focused on the opening portion 52. FIG.5 illustrates a first position z1 and a second position z2 on theZ-axis. The first position z1 is any position between the first face Fa1and the second face Fa2. The second position z2 is any position closerto the communication chamber 34 than the first position z1. In otherwords, the second position z2 is positioned in the Z-axis negativedirection with respect to the first position z1. As illustrated as anexample in FIG. 5, an inner circumferential surface of the openingportion 52 is an inclined surface in which an inner diameter φ1 at thefirst position z1 is smaller than an inner diameter φ2 at the secondposition z2 (φ1<φ2). Accordingly, an inner diameter of the openingportion 52 is the smallest in the first face Fa1 and is the largest inthe second face Fat. In other words, the opening portion 52 is formed ina tapered shape in which the communication chamber 34 side has a largediameter.

The liquid flow path 33 and each nozzle N are cleaned with a cleaningsolution in a process (hereinafter, referred to as a “cleaningprocess”), which is in a manufacturing process of the liquid ejectinghead 24, after the flow path structure 30 and the liquid ejecting unit40 are assembled. The communication chamber 34, the opening portion 52,and the communication flow path 35 are used in the cleaning process.Specifically, in the cleaning process, the cleaning solution suppliedfrom the outside to the plurality of nozzles N passes through the liquidflow path 33, the opening portion 52, the communication chamber 34, andthe communication flow path 35 and is discharged through the releaseport 38. With the flow of the cleaning solution described above, foreignmatters present at the vicinity of the nozzles N are discharged throughthe release port 38. The opening portion 52 is closed after performingthe cleaning process.

As illustrated as an example in FIG. 4, a blocking member 60 isaccommodated in the communication chamber 34. The blocking member 60 isa member that closes the opening portion 52 after the cleaning processhas been performed. In other words, when the liquid ejecting head 24 isin the operating state, the opening portion 52 is closed by the blockingmember 60. The blocking member 60 is biased in a Z-axis positivedirection with a biasing member 342 provided between the blocking member60 and the upper surface of the communication chamber 34. The biasingmember 342 is, for example, a spring. When viewed in the Z-axisdirection, a cross-sectional area of the blocking member 60 is largerthan a cross-sectional area of the communication port 341. Specifically,an external dimension of the blocking member 60 is larger than an innerdiameter of the communication port 341. Accordingly, for example, duringthe cleaning process or when the liquid ejecting head 24 is inclinedagainst the vertical direction, the possibility of the blocking member60 passing through the communication port 341 and being discharged canbe reduced.

The blocking member 60 includes an elastic member 61 and a shaft member62. The elastic member 61 is an elastic body formed of an elasticmaterial such as rubber, elastomer, or the like. The shaft member 62 isan elongated member formed of a material having a rigidity that ishigher than that of the elastic member 61. For example, the elasticmember 61 is formed of silicone rubber or butyl rubber having an Asker Chardness of 13 to 30 points, and the shaft member 62 is formed ofengineering plastic. The elastic member 61 is provided at an end portionof the shaft member 62. With the above configuration, compared with aconfiguration in which the elastic member 61 alone is accommodated inthe communication chamber 34, the location and the position of theelastic member 61 can be stabilized.

FIG. 6 is a trihedral figure illustrating, as an example, aconfiguration of the blocking member 60, and FIG. 7 is a schematicdiagram of the elastic member 61 separated from the shaft member 62. Theelastic member 61 is a shell-shaped structure in which a front end isformed in a hemispherical curved surface. A planar first mounting faceFb1 is formed on the elastic member 61. A bottomed recessed portion 610is formed in the first mounting face Fb1.

The shaft member 62 is a component formed integrally by injectionmolding a resin material, for example, and includes a shaft body 620, afirst flange portion 621, a second flange portion 622, and a support endportion 623. The shaft body 620 is a rodlike portion that extendslinearly. A plurality of groove portions 63 that extend along thecentral axis of the shaft body 620 are formed in an outercircumferential surface of the shaft body 620 at intervals in thecircumferential direction. Specifically, the cross-sectional shape ofthe shaft body 620 is substantially cruciform.

The first flange portion 621 is formed in one end portion of the shaftbody 620, and the second flange portion 622 is formed in the other endportion of the shaft body 620. In other words, the shaft body 620 issituated between the first flange portion 621 and the second flangeportion 622. The first flange portion 621 and the second flange portion622 are each a flat plate-shaped portion that protrudes in a flange likemanner in the radial direction from the outer circumferential surface ofthe shaft body 620. A plurality of notches 64 are formed at intervals inthe circumferential direction in the outer circumferential surface ofeach of the first flange portion 621 and the second flange portion 622.Specifically, a cross-sectional shape of each of the first flangeportion 621 and the second flange portion 622 is substantially cruciformwhen viewed in the longitudinal direction of the shaft member 62. Evenwhen the blocking member 60 is in contact with the inner wall surface ofthe communication chamber 34, the cleaning solution can pass through thegroove portions 63 and the notches 64. In other words, there is anadvantage in that a path of the cleaning solution can be obtainedregardless of the position of the blocking member 60.

The support end portion 623 is provided on a side opposite the shaftbody 620 with respect to the first flange portion 621. In other words,the first flange portion 621 is situated between the shaft body 620 andthe support end portion 623. The support end portion 623 protrudessubstantially vertically from a surface (hereinafter referred to as a“second mounting face”) Fb2 of the first flange portion 621, which is ona side opposite the shaft body 620. As understood from FIG. 4, the innerdiameter of the opening portion 52 is larger than an outer diameter ofthe support end portion 623. Specifically, the outer diameter of thesupport end portion 623 is smaller than the inner diameter of theopening portion 52 at the first face Fa1 (in other words, the largestvalue of the inner diameter). In other words, an opening area of theopening portion 52 is larger than a cross-sectional area of the supportend portion 623. Accordingly, the support end portion 623 can beinserted in the opening portion 52.

As illustrated as an example in FIGS. 6 and 7, the elastic member 61 isfixed to the shaft member 62 while in a state in which the support endportion 623 of the shaft member 62 is fitted in the recessed portion 610of the elastic member 61. In other words, a front end of the support endportion 623 is covered by the elastic member 61. Accordingly, thepossibility of the partitioning wall portion 51 being damaged due to thesupport end portion 623 impacting thereagainst is reduced. Asillustrated as an example in FIGS. 6 and 7, the first mounting face Fb1of the elastic member 61 and the second mounting face Fb2 of the shaftmember 62 oppose each other when the elastic member 61 is fixed to theshaft member 62. Note that a height of the support end portion 623 and adepth of the recessed portion 610 are substantially the same.Accordingly, the first mounting face Fb1 and the second mounting faceFb2 are in contact with each other without any gap in between eachother. As described above, in the first exemplary embodiment, theelastic member 61 can be provided on the shaft member 62 with a simpleconfiguration in which the support end portion 623 of the shaft member62 is fitted in the recessed portion 610 of the elastic member 61.

As illustrated as an example in FIG. 6, outer diameters of the firstflange portion 621 and the second flange portion 622 are larger than anouter diameter of the elastic member 61. Accordingly, when viewed in anaxial direction of the shaft member 62, peripheral portions of the firstflange portion 621 and the second flange portion 622 protrude from theouter circumferential edge of the elastic member 61. As understood fromthe above description, the shaft member 62 of the first exemplaryembodiment viewed in the axial direction includes portions positionedoutside the outer circumferential edge of the elastic member 61. Theabove configuration has an advantage in that the location and theposition of the blocking member 60 can be maintained in a stable mannerby having the portions positioned outside the outer circumferential edgeof the elastic member 61 in the shaft member 62 (in other words, thefirst flange portion 621 and the second flange portion 622) be incontact with the inner wall surface of the communication chamber 34.

As illustrated as an example in FIG. 4, the opening portion 52 is closedby inserting the elastic member 61 in the opening portion 52.Accordingly, when the liquid ejecting head 24 is in the operating state,the ink inside the liquid flow path 33 does not enter the communicationchamber 34 through the opening portion 52.

In a state in which the opening portion 52 is closed by the elasticmember 61, a portion of the elastic member 61 protrudes to the liquidflow path 33 from the first face Fa1 of the partitioning wall portion51. Specifically, a portion of the front end of the elastic member 61protrudes from the first face Fa1 in the Z-axis positive direction. Inthe above state, the elastic member 61 is caught by an corner portion511 formed by the first face Fa1 and the inner circumferential surfaceof the opening portion 52. In other words, the first face Fa1 functionsas a holding surface that holds the elastic member 61. As understoodfrom the above description, the first exemplary embodiment has anadvantage in that, compared with a configuration in which the elasticmember 61 does not protrude from the first face Fa1, the elastic member61 can be held inside the opening portion 52 in a stable manner.

Furthermore, as illustrated as an example in FIG. 4, in a state in whichthe opening portion 52 is closed by the elastic member 61, the supportend portion 623 is inserted in the opening portion 52. Specifically, thefront end of the support end portion 623 is situated between the firstface Fa1 and the second face Fat. According to the above configuration,compared with a configuration in which the support end portion 623 isnot inserted in the opening portion 52, the possibility of the elasticmember 61 detaching from the opening portion 52 is reduced.

FIG. 8 is an explanatory drawing of the cleaning process, which is inthe method of manufacturing the liquid ejecting head 24, in which theinner flow path of the liquid ejecting unit 40 is cleaned. As describedabove, the cleaning process is performed after the flow path structure30 and the liquid ejecting unit 40 has been assembled. In process P0 inwhich the cleaning process is started, as illustrated as an example inFIG. 8, the blocking member 60 is urged against the partitioning wallportion 51 with the biasing member 342. Furthermore, in the cleaningprocess, the introduction port 36 is closed by a sealing member formedof an elastic material such as, for example, rubber or elastomer.Accordingly, while the elastic member 61 is not inserted inside theopening portion 52, the opening portion 52 is closed by the elasticmember 61 adhering to an inner circumferential edge of the openingportion 52 in the second face Fat.

In process P1 in FIG. 8, in a state in which the plurality of nozzles Nof the liquid ejecting unit 40 is immersed in a cleaning solution W, asuction apparatus 70 coupled to the release port 38 is activated. Withthe action of the suction apparatus 70, the insides of the communicationflow path 35 and the communication chamber 34 are controlled to have anegative pressure. By being suctioned from the release port 38 side, theblocking member 60 moves in the Z-axis negative direction from theposition in process P0. In other words, the blocking member 60 isseparated from the partitioning wall portion 51. Furthermore, bycanceling the closed state of the opening portion 52, the negativepressure inside the communication flow path 35 and the communicationchamber 34 acts on the nozzles N through the liquid flow path 33 and theflow paths inside the liquid ejecting unit 40. Accordingly, the cleaningsolution W is supplied to the liquid flow path 33 through the pluralityof nozzles N and, further, passes through the opening portion 52 andflows into the communication chamber 34. Furthermore, the cleaningsolution W passing through the communication flow path 35 is, throughthe release port 38, ultimately discharged from the communicationchamber 34. As understood from the above description, by supplying thecleaning solution W to the communication chamber 34 through theplurality of nozzles N, the liquid flow path 33, and the opening portion52 and by discharging the cleaning solution W inside the communicationchamber 34 through the communication port 341, the plurality of nozzlesN and the liquid flow path 33 are cleaned. Note that in process P1, theplurality of nozzles N and the liquid flow path 33 may be cleaned bypressurizing and supplying the cleaning solution W to the plurality ofnozzles N of the liquid ejecting unit 40.

In the first exemplary embodiment, the opening portion 52 branched offfrom the liquid flow path 33 at a point between the nozzles N and thefilter 321 is in communication with the communication chamber 34.Accordingly, even when the filter 321 in which the through holes areequivalent to or smaller than the inner diameter of each nozzle N isemployed, the cleaning solution W can be supplied to the release port 38without passing through the filter 321. Accordingly, not only the fineforeign matters in the vicinity of each nozzle N, large foreign matterslarger than the diameter of the nozzle N can be removed as well.

After the process P1 has been performed, in process P2, by activatingthe suction apparatus 70 while the plurality of nozzles N are notimmersed in the cleaning solution W, gas such as air or the like isintroduced through the plurality of nozzles N. Accordingly, the cleaningsolution W is discharged from inside the liquid ejecting head 24. Notethat the inner space of the flow path structure 30 is not completelydry. By having moisture of the cleaning solution W appropriately remainbetween the elastic member 61 and the inner circumferential surface ofthe opening portion 52, the opening portion 52 is closed without anygap. Accordingly, in process P3 and process P4 described below as anexample, the possibility of gas leaking out from the gap between theopening portion 52 and the elastic member 61 is reduced.

After process P2 has been performed, in process P3, gas G having apredetermined pressure p1 is supplied to the release port 38 from an aircharging system 71. The air charging system 71 is, for example, a pumpthat sends out air at an optional pressure. The gas G sent out from theair charging system 71 is supplied to the communication chamber 34through the release port 38 and the communication flow path 35. Thepressure p1 of the gas G is set to a value smaller than a pressure p2needed to insert the elastic member 61 in the opening portion 52.Accordingly, at the stage of process P3, the elastic member 61 is notinserted in the opening portion 52. In process P3, a measuring apparatus72 measures the pressure inside the communication chamber 34.

At the stage of process P3, a state in which the elastic member 61closes the opening portion 52 is expected; however, in actuality, astate in which the position of the blocking member 60 with respect tothe opening portion 52 is displaced and in which the opening portion 52is not closed is assumed. When the opening portion 52 is not closed, thegas G supplied to the communication chamber 34 from the air chargingsystem 71 flows out to the liquid flow path 33 through the openingportion 52. When the gas G from the air charging system 71 is suppliedinto the liquid ejecting unit 40 from the liquid flow path 33, there isa possibility of the compliance portions 48 being damaged due to theincrease in pressure caused by the gas G, or, due to the gas G, there isa possibility of the foreign matters present in the communicationchamber 34 or the communication flow path 35 moving to the liquidejecting unit 40 and entering the nozzles N.

In consideration of the above circumstances, in the first exemplaryembodiment, determination is made on whether the opening portion 52 isclosed by the elastic member 61. In a state in which the opening portion52 is not appropriately closed by the elastic member 61, since the gas Gin the communication chamber 34 leaks to the liquid flow path 33 throughthe opening portion 52, the pressure in the communication chamber 34 isbelow a predetermined threshold value. Accordingly, determination ofwhether the opening portion 52 is appropriately closed is made based onwhether the pressure measured by the measuring apparatus 72 exceeds thethreshold value. When the pressure measured by the measuring apparatus72 is below the threshold value, the position of the blocking member 60is corrected so that the opening portion 52 is closed by the elasticmember 61. As understood from the above description, determination ofwhether the opening portion 52 is closed is made based on the pressuremeasured by the measuring apparatus 72.

On the other hand, when in a state in which the opening portion 52 isappropriately closed by the elastic member 61, the pressure in thecommunication chamber 34 exceeds the threshold value. When the pressuremeasured by the measuring apparatus 72 exceeds the threshold value,process P4 is started. In process P4, the gas G having the pressure p2that exceeds the pressure p1 is supplied to the release port 38 from theair charging system 71. The gas G sent out from the air charging system71 is supplied to the communication chamber 34 through the release port38 and the communication flow path 35. The elastic member 61 enters theopening portion 52 while being elastically deformed due to being pressedby the gas G having the pressure p2 supplied from the air chargingsystem 71.

In a state in which the gas G having the pressure p2 is supplied to thecommunication chamber 34, as illustrated in FIG. 9, the front end of theelastic member 61 protrudes into the liquid flow path 33 from the firstface Fa1. Furthermore, the support end portion 623 penetrates throughthe opening portion 52. In other words, the front end of the support endportion 623 protrudes into the liquid flow path 33 from the first faceFa1. In the above state, the supply of the gas G with the air chargingsystem 71 is stopped. When the supply of the gas G is stopped, asillustrated as an example in FIG. 4, the elastic member 61 is maintainedin a state inserted in the opening portion 52. As understood from theabove description, the elastic member 61 is press-fitted into theopening portion 52 by the gas G supplied from the communication port341. When the elastic member 61 is press-fitted into the opening portion52 in process P4, the release port 38 is closed by the closing member381.

As a configuration that prevents the ink from flowing out through therelease port 38 when the liquid ejecting head 24 is in a use state, aconfiguration (hereinafter, referred to as a “comparative example”) inwhich the elastic member 61 is omitted is assumed as well. In thecomparative example, the ink is prevented from flowing out through therelease port 38 by closing the release port 38 with the closing member381. However, in the comparative example, foreign matters remaining inthe communication chamber 34 or in the communication flow path 35 in themanufacturing process may move to the liquid flow path 33 and, as aresult, the foreign matters may enter the nozzles N. In contrast to thecomparative example, in the first exemplary embodiment, the openingportion 52 that communicates the liquid flow path 33 and thecommunication chamber 34 to each other is closed by the elastic member61. Accordingly, even if foreign matters were to remain in thecommunication chamber 34 or the communication flow path 35 in themanufacturing process, when in the operating state in which the openingportion 52 is closed by the elastic member 61, the foreign matters willbe prevented from moving to the liquid flow path 33.

In the first exemplary embodiment, the elastic member 61 is press-fittedinto the opening portion 52 with the gas G supplied to the communicationchamber 34 through the communication port 341. Accordingly, there is anadvantage in that, compared with a configuration in which, for example,the elastic member 61 is press-fitted into the opening portion 52 bymechanically pressing the elastic member 61 with a tool, the elasticmember 61 can be pressed against the opening portion 52 in a uniformmanner. Furthermore, in the first exemplary embodiment, since thecommunication flow path 35 includes the portions that extend along theZ-axis and the portion that intersects the Z-axis, it is difficult topress the elastic member 61 with a tool inserted through the releaseport 38. In the first exemplary embodiment, since the elastic member 61is press-fitted into the opening portion 52 with the gas G, there is anadvantage in that the elastic member 61 can be easily inserted in theopening portion 52 even under a circumstance in which the use of thetool is difficult due to the shape of the communication flow path 35.

Note that in a configuration in which the first mounting face Fb1 of theelastic member 61 and the second mounting face Fb2 of the shaft member62 oppose each other with a gap in between, a pressure may be applied tothe first mounting face Fb1 with the gas G supplied from the aircharging system 71 and, as a result, the elastic member 61 may becomedetached from the shaft member 62. In the first exemplary embodiment,since the first mounting face Fb1 and the second mounting face Fb2 arein contact with each other with no gap in between, the first mountingface Fb1 can be prevented from being pressurized with the gas G suppliedfrom the air charging system 71. Accordingly, the possibility of theelastic member 61 being detached from the shaft member 62 can bereduced.

In the first exemplary embodiment, the inner diameter φ1 of the openingportion 52 at the first position z1 is smaller than the inner diameterφ2 of the opening portion 52 at the second position z2. Accordingly,compared with a configuration in which the inner diameter of the openingportion 52 is uniform along the Z-axis, there is an advantage in thatthe insertion of the elastic member 61 into the opening portion 52 isfacilitated. Note that even in a configuration in which, rather than theentire inner circumferential surface of the opening portion 52 being aninclined surface, a portion of the inner circumferential surface is aninclined surface, the insertion of the elastic member 61 into theopening portion 52 is facilitated when compared with a configuration inwhich the inner diameter of the opening portion 52 is uniform along theZ-axis.

Second Exemplary Embodiment

A description of a second exemplary embodiment will be given. Note thatin the following examples, elements having functions similar to those ofthe first exemplary embodiment will be denoted with the referencenumerals used in the description of the first exemplary embodiment, anddetailed description of the elements will be omitted appropriately.

FIG. 10 is an enlarged cross-sectional view of a vicinity of thecommunication chamber 34 according to a second exemplary embodiment.FIG. 11 is a side view of the blocking member 60 according to the secondexemplary embodiment. In the second exemplary embodiment, the shape ofthe elastic member 61 is different from that of the first exemplaryembodiment. Other configurations are similar to those of the firstexemplary embodiment.

As illustrated as an example in FIGS. 10 and 11, the elastic member 61of the second exemplary embodiment includes, along the central axis ofthe elastic member 61, a first portion 611, a second portion 612, and athird portion 613. The first portion 611, the second portion 612, andthe third portion 613 are integrally formed of rubber or elastomer, forexample. The recessed portion 610 extending through the first portion611, the second portion 612, and the third portion 613 is formed in thefirst mounting face Fb1.

The first portion 611 is a front end side portion of the elastic member61. The second portion 612 is a base end side portion of the elasticmember 61. In other words, the first mounting face Fb1 is a surface ofthe second portion 612 opposite the first portion 611. The third portion613 is a portion situated between the first portion 611 and the secondportion 612. In other words, the second portion 612 is situated betweenthe third portion 613 and the first flange portion 621 of the shaftmember 62. A cross-sectional area of the third portion 613 is smallerthan a cross-sectional area of the first portion 611 and across-sectional area of the second portion 612. Specifically, asunderstood from FIG. 10, an outer diameter of the first portion 611 andan outer diameter of the second portion 612 are larger than an innerdiameter of the opening portion 52 at the first face Fa1 (in otherwords, the minimum value of the inner diameter). On the other hand, anouter diameter of the third portion 613 is equivalent to or smaller thanthe inner diameter of the opening portion 52 at the first face Fa1.

As illustrated as an example in FIG. 10, in a state in which the elasticmember 61 is inserted in the opening portion 52, the first portion 611is situated in the liquid flow path 33. In other words, the firstportion 611 is situated in the Z-axis positive direction with respect tothe first face Fa1. The second portion 612 is situated in thecommunication chamber 34. In other words, the second portion 612 issituated in the Z-axis negative direction with respect to the secondface Fat. The third portion 613 is situated inside the opening portion52.

An effect similar to the first exemplary embodiment can be provided inthe second exemplary embodiment as well. Furthermore, in the secondexemplary embodiment, since the cross-sectional area of the thirdportion 613 between the first portion 611 and the second portion 612 issmaller than the cross-sectional areas of the first portion 611 and thesecond portion 612, the elastic member 61 can be inserted in the openingportion 52 more easily compared with a configuration in which thecross-sectional area of the elastic member 61 is uniform along thecentral axis. Furthermore, there is an advantage in that the elasticmember 61 inserted in the opening portion 52 does not easily becomedetached.

Third Exemplary Embodiment

FIG. 12 is an enlarged cross-sectional view of a vicinity of thecommunication chamber 34 according to a third exemplary embodiment. FIG.13 is a cross-sectional view of the blocking member 60 according to thethird exemplary embodiment. In the third exemplary embodiment, the shapeof the support end portion 623 of the shaft member 62 is different fromthat of the first exemplary embodiment. Other configurations are similarto those of the first exemplary embodiment.

As illustrated as an example in FIGS. 12 and 13, the support end portion623 of the shaft member 62 according to the third exemplary embodimentincludes, along the central axis of the shaft member 62, a first shaftportion 651 and a second shaft portion 652. The second shaft portion 652is a portion on the front end side of the support end portion 623. Inother words, the second shaft portion 652 is situated on the liquid flowpath 33 side with respect to the first shaft portion 651. The firstshaft portion 651 is situated between the second shaft portion 652 andthe first flange portion 621. An outer diameter of the second shaftportion 652 is larger than an outer diameter of the first shaft portion651. In other words, the second shaft portion 652 has a diameter that islarger than that of the first shaft portion 651. In other words, across-sectional area of the second shaft portion 652 is larger than across-sectional area of the first shaft portion 651.

As illustrated as an example in FIG. 12, the outer diameter of thesecond shaft portion 652 is smaller than the inner diameter of theopening portion 52 at the first face Fa1 (in other words, the minimumvalue of the inner diameter). Accordingly, the first shaft portion 651and the second shaft portion 652 can pass through the opening portion52. As illustrated as an example in FIG. 12, in a state in which theelastic member 61 is inserted in the opening portion 52, the secondshaft portion 652 is situated in the liquid flow path 33. In otherwords, the second shaft portion 652 is situated in the Z-axis positivedirection with respect to the first face Fa1. On the other hand, thefirst shaft portion 651 is situated in the Z-axis negative directionwith respect to the first face Fa1.

An effect similar to that of the first exemplary embodiment can beprovided in the third exemplary embodiment as well. Furthermore, in thethird exemplary embodiment, by inserting the second shaft portion 652that has a diameter that is larger than that of the first shaft portion651 in the opening portion 52, the possibility of the elastic member 61detaching from the opening portion 52 can be reduced.

Fourth Exemplary Embodiment

FIG. 14 is a perspective view of the first flange portion 621 and thesupport end portion 623 of the shaft member 62 according to a fourthexemplary embodiment illustrated in an enlarged manner. As illustratedas an example in FIG. 14, in the shaft member 62 of the fourth exemplaryembodiment, a groove portion 66 is formed across the second mountingface Fb2 of the first flange portion 621 and a lateral surface 654 ofthe support end portion 623. Specifically, the groove portion 66includes a first groove portion 661 and a second groove portion 662 thatare continuous to each other. The first groove portion 661 is adepression in the second mounting face Fb2 and extends in the radialdirection from the lateral surface 654 of the support end portion 623 toan outer circumferential edge of the first flange portion 621. Thesecond groove portion 662 is a depression in the lateral surface 654 ofthe support end portion 623 and extends across the entire length of thesupport end portion 623 in a direction of the central axis. The firstgroove portion 661 is closed by the first mounting face Fb1 of theelastic member 61, and the second groove portion 662 is closed by theinner circumferential surface of the recessed portion 610 of the elasticmember 61. In other words, a flow path from a portion external to theelastic member 61 to the inner side of the recessed portion 610 isformed.

An effect similar to that of the first exemplary embodiment can beprovided in the fourth exemplary embodiment as well. Furthermore, in thefourth exemplary embodiment, the flow path from the outer portion to theinner portion of the elastic member 61 is formed with the groove portion66. Accordingly, the gas G supplied to the communication chamber 34 fromthe air charging system 71 in process P4 is supplied to the inner sideof the elastic member 61 through the above flow path. In other words,the elastic member 61 is pressed by the gas G from the inner side.Accordingly, the fourth exemplary embodiment has an advantage in thatthe insertion of the elastic member 61 into the opening portion 52 isfacilitated.

Fifth Exemplary Embodiment

FIG. 15 is a cross-sectional view of a portion of the liquid ejectinghead 24 according to a fifth exemplary embodiment. As illustrated as anexample in FIG. 15, a circulation flow path 81 that communicates theliquid storage chamber R and the circulation port 83 is formed in theflow path structure 30 of the fifth exemplary embodiment. In the inkthat is stored in the liquid storage chamber R, the ink that is notsupplied to the nozzles N is discharged to the circulation flow path 81.The ink discharged to the circulation flow path 81 reaches thecirculation port 83 through a storage chamber 82 in the circulation flowpath 81. A filter 821 that collects foreign matters mixed in the ink isprovided in the storage chamber 82. Similar to the filter 321 describedabove, a plurality of through holes in which the inner diameters aresmaller than that of each nozzle N are formed in the filter 821. Theink, from the circulation flow path 81, that has reached the circulationport 83 is circulated to the supply ports 461 of the liquid ejectingunit 40 with a circulation mechanism 84 including, for example, a pumpand the like.

As illustrated as an example in FIG. 15, the opening portion 52 isformed so as to branch off from the circulation flow path 81.Specifically, the opening portion 52 branches off from a point betweenthe liquid storage chamber R and the storage chamber 82 in thecirculation flow path 81. The opening portion 52 is formed in thepartitioning wall portion 51 and communicates the circulation flow path81 and the communication chamber 34 to each other. The configurations ofthe communication chamber 34 and the communication flow path 35, and theconfiguration of the blocking member 60 accommodated in thecommunication chamber 34 are similar to those of the exemplaryembodiments described above.

In the cleaning process in the fifth exemplary embodiment, the cleaningsolution W supplied to the plurality of nozzles N from a portionexternal thereto passes through the liquid storage chamber R, thecirculation flow path 81, the opening portion 52, the communicationchamber 34, and the communication flow path 35 and is discharged throughthe release port 38. In other words, the cleaning solution W is suppliedto the release port 38 through the opening portion 52, the communicationchamber 34, and the communication flow path 35 without passing throughthe filter 821. An effect similar to that of the first exemplaryembodiment can be provided in the fifth exemplary embodiment as well.

Modifications

Each of the exemplary embodiments described above as examples can bemodified in various ways. Specific modification modes that can beapplied to the configurations described above will be described below asexamples. Two or more optionally selected modes from the examples belowcan be merged as appropriate as long as they do not contradict eachother.

1. In the exemplary embodiments described above, a configuration hasbeen illustrated in which the front end of the support end portion 623is covered by the elastic member 61. However, as illustrated as anexample in FIG. 16, the front end of the support end portion 623 may beprotruded from the elastic member 61. In the configuration in FIG. 16,the total length of the support end portion 623 is longer than the totallength of the elastic member 61. Furthermore, a through hole is formedin the elastic member 61. Accordingly, the support end portion 623penetrates through the elastic member 61. In other words, the front endof the support end portion 623 is exposed from the elastic member 61.However, in the configuration in FIG. 16, the front end of the supportend portion 623 formed of a hard material may impact the partitioningwall portion 51 in the cleaning process. Accordingly, from the viewpointof reducing the possibility of the partitioning wall portion 51 becomingdamaged by the impact of the support end portion 623, the configuration,as in the exemplary embodiments described above, in which the front endof the support end portion 623 is covered by the elastic member 61 ispreferable.

2. In the exemplary embodiments described above, a configuration inwhich a portion of the elastic member 61 protrudes in the liquid flowpath 33 from the first face Fa1 of the partitioning wall portion 51 hasbeen illustrated as an example However, as illustrated as an example inFIG. 17, a configuration in which the front end of the elastic member 61is situated in the Z-axis negative direction with respect to the firstface Fa1 is employed as well. In other words, the configuration in whicha portion of the elastic member 61 protrudes in the liquid flow path 33is not essential.

3. In the exemplary embodiments described above, a configuration inwhich the first mounting face Fb1 of the elastic member 61 and thesecond mounting face Fb2 of the shaft member 62 adhere to each other hasbeen given as an example; however, as illustrated as an example in FIG.18, a configuration in which the first mounting face Fb1 and the secondmounting face Fb2 oppose each other with a predetermined gap in betweenis employed as well. In the configuration in FIG. 18, the total lengthof the support end portion 623 is longer than the depth of the recessedportion 610 of the elastic member 61.

4. In the exemplary embodiments described above, the elastic member 61and the shaft member 62 formed separately are fixed to each other;however, the method of manufacturing the blocking member 60 is notlimited to the example illustrated above. For example, the elasticmember 61 and the shaft member 62 may be integrally formed by two colormolding. When the blocking member 60 is two color molded, similar to theexamples of the exemplary embodiments described above, the firstmounting face Fb1 of the elastic member 61 and the second mounting faceFb2 of the shaft member 62 adhere to each other.

5. In the exemplary embodiments described above, an example of aconfiguration in which the first face Fa1 of the partitioning wallportion 51 is continuous to the inner wall surface of the liquid flowpath 33 has been described; however, as illustrated in FIG. 19, a step δmay be formed between the first face Fa1 of the partitioning wallportion 51 and an inner wall surface 331 of the liquid flow path 33. Thefront end portion of the elastic member 61 is accommodated in the spacecorresponding to the step δ. The first face Fa1 is an annular areaformed concentrically with the opening portion 52 when in plan view inthe Z-axis direction. A width ω of the first face Fa1 is set equivalentto or larger than 1/50 of an inner diameter φ of the opening portion 52in the first face Fa1(ω≥φ/50). With the above configuration, the frontend portion of the elastic member 61 can be accommodated inside the stepδ.

6. In the exemplary embodiments described above, the blocking member 60that includes the elastic member 61 and the shaft member 62 has beendescribed as an example; however, the shaft member 62 may be omitted.However, the configuration of the exemplary embodiments described abovein which the elastic member 61 is provided on the hard shaft member 62has an advantage in that the location and the position of the elasticmember 61 become stable.

7. In process P3 or process P4 in FIG. 8, the elastic member 61 may besoftened by heating the elastic member 61. For example, in process P3,the elastic member 61 is heated to at least the glass transitiontemperature. With the above method, since the elastic member 61 issufficiently inserted in the opening portion 52, the possibility of theelastic member 61 becoming detached from the opening portion 52 when theliquid ejecting head 24 is in the operating state can be reduced.

8. In process P4 in FIG. 8, the elastic member 61 is elasticallydeformed by having the elastic member 61 pressed against thepartitioning wall portion 51 with the gas G supplied to thecommunication chamber 34. By contracting in the Z-axis direction, theelastic member 61 expands in the radial direction. In the exemplaryembodiments described above, an example in which, in process P4, theouter circumferential surface of the elastic member 61 and the innerwall surface of the communication chamber 34 oppose each other with agap in between has been described. However, as illustrated as an examplein FIG. 20, in process P4, the outer circumferential surface of theelastic member 61 may be in contact with the inner wall surface of thecommunication chamber 34. With the above configuration, since thedeformation of the elastic member 61 in the radial direction isrestricted, the elastic member 61 can be efficiently advanced in theZ-axis direction. Accordingly, the elastic member 61 is sufficientlyinserted in the opening portion 52 and, as a result, the elastic member61 can be held inside the opening portion 52 in a stable manner.

9. In the exemplary embodiments described above, an example of a taperedopening portion 52 in which the diameter is large in the Z-axis negativedirection has been described; however, the shape of the opening portion52 is not limited to the example described above. For example, asillustrated as an example in FIG. 21, a tapered opening portion 52 inwhich the diameter is large in the Z-axis positive direction may beformed in the partitioning wall portion 51. Alternatively, a straighttubular opening portion 52 in which the inner diameter is uniform acrossthe entire length in the Z-axis direction may be formed.

10. In the exemplary embodiments described above, while a serial liquidejecting apparatus 100 that reciprocates the liquid ejecting head 24along the X-axis has been described as an example, a line liquidejecting apparatus in which a plurality of nozzles N are distributedacross the entire width of the medium 11 is applied to the presentdisclosure as well.

11. The liquid ejecting apparatus 100 described as an example in theembodiments described above may be employed in various apparatuses otherthan an apparatus dedicated to printing, such as a facsimile machine anda copier. Note that the application of the liquid ejecting apparatus isnot limited to printing. For example, a liquid ejecting apparatus thatejects a coloring material solution is used as a manufacturing apparatusthat forms a color filter of a display device such as a liquid crystaldisplay panel. Furthermore, a liquid ejecting apparatus that ejects aconductive material solution is used as a manufacturing apparatus thatforms wiring and electrodes of a wiring substrate. Furthermore, a liquidejecting apparatus that ejects a solution of an organic matter relatedto a living body is used, for example, as a manufacturing apparatus thatmanufactures a biochip.

Additional Statement

For example, the following configurations are comprehended from theconfigurations described above as examples.

A liquid ejecting head according to a suitable aspect (first aspect)includes a nozzle that ejects a liquid, a liquid flow path incommunication with the nozzle, a communication chamber including acommunication port configured to communicate with atmospheric air, apartitioning wall portion provided between the liquid flow path and thecommunication chamber, the partitioning wall portion including anopening portion that communicates the liquid flow path and thecommunication chamber to each other, and an elastic member that closesthe opening portion. In the above aspect, the opening portion thatcommunicates the liquid flow path and the communication chamber to eachother is closed by the elastic member; accordingly, compared with aconfiguration in which the communication port of the communicationchamber is closed by the elastic member, foreign matters can besuppressed from entering the nozzle from the communication chamber. Notethat “the communication port configured to communicate with atmosphericair” includes a state in which the communication port actuallycommunicates with the atmospheric air, and a state in which thecommunication port or a flow path in communication with thecommunication port is closed by a closing member.

In a specific example (a second aspect) of the first aspect, thepartitioning wall portion includes a first face that opposes the liquidflow path, and a second face that opposes the communication chamber, anda portion of the elastic member protrudes from the first face to aliquid flow path side. In the above aspect, the elastic member protrudesfrom the first face to the liquid flow path side. Accordingly, comparedwith a configuration in which the elastic member does not protrude fromthe first face to the liquid flow path side, the elastic member can beheld inside the opening portion in a stable manner. The “first face thatopposes the liquid flow path” is, in other words, a surface thatconstitutes an inner wall surface of the liquid flow path. Similarly,the “second face that opposes the communication chamber” is, in otherwords, a surface that constitutes an inner wall surface of thecommunication chamber.

In a specific example (a third aspect) of the first or second aspect,the elastic member is press-fitted into the opening portion with a gassupplied through the communication port. According to the above aspect,it will be possible to press-fit the elastic member in the openingportion with the gas supplied to the communication chamber through thecommunication port. According to the method of press-fitting the elasticmember in the opening portion by applying pressure to the elastic memberwith the gas, compared with a configuration in which, for example, theelastic member is mechanically pressed with a tool, there is anadvantage in that the elastic member can be pressed against the openingportion in a uniform manner.

In a specific example (a fourth aspect) of any of the first to thirdaspects, the elastic member includes, along a central axis of theelastic member, a first portion situated on a liquid flow path side, asecond portion situated on a communication chamber side, and a thirdportion situated between the first portion and the second portion, across-sectional area of the third portion is smaller thancross-sectional areas of the first portion and the second portion. Inthe above aspect, since the cross-sectional area of the third portion issmaller than the cross-sectional areas of the first portion and thesecond portion, compared with a configuration in which thecross-sectional area of the elastic member is uniform, insertion of theelastic member in the opening portion is facilitated. Furthermore, thereis an advantage in that the elastic member inserted in the openingportion does not easily become detached.

In a specific example (a fifth aspect) of any of the first to fourthaspects, an inner circumferential surface of the opening portionincludes an inclined surface in which an inner diameter at a firstposition in a direction of a central axis of the opening portion issmaller than an inner diameter at a second position that is closer tothe communication chamber than the first position. In the above aspect,the inner diameter of the opening portion at the first position issmaller than the inner diameter of the opening portion at the secondposition that is closer to the communication chamber than the firstposition. Accordingly, compared with a configuration in which the innerdiameter of the opening portion is uniform along the central axis,insertion of the elastic member in the opening portion is facilitated.

The liquid ejecting head according to a specific example (a sixthaspect) of any of the first to fifth aspects further includes a shaftmember that has a rigidity that is higher than that of the elasticmember, in which the elastic member is provided on the shaft member.According to the above aspect, since the elastic member is provided on ashaft member that has a rigidity that is higher than that of the elasticmember, the location and the position of the elastic member can bestabilized.

In a specific example (a seventh aspect) of the sixth aspect, the shaftmember includes a support end portion situated on a liquid flow pathside, and the elastic member includes a recessed portion that fits thesupport end portion thereto. In the above aspect, the elastic member canbe provided on the shaft member with a simple configuration in which therecessed portion of the elastic member is fitted to the support endportion of the shaft member.

In a specific example (an eighth aspect) of the seventh aspect, an innerdiameter of the opening portion is larger than an outer diameter of thesupport end portion. In the above aspect, since the inner diameter ofthe opening portion is larger than the outer diameter of the support endportion, the support end portion can be inserted in the opening portion.Accordingly, the elastic member can be reliably inserted in the openingportion.

In a specific example (a ninth aspect) of the seventh or eighth aspect,the support end portion is inserted in the opening portion. In the aboveaspect, since the support end portion is inserted in the openingportion, a possibility of the elastic member detaching from the openingportion can be reduced.

In a specific example (a tenth aspect) according to any one of theseventh to ninth aspects, a front end of the support end portion iscovered by the elastic member. In the above aspect, since the front endof the support end portion is covered by the elastic member, forexample, the possibility of the partitioning wall portion becomingdamaged by the impact of the support end portion can be reduced.

In a specific example (an eleventh aspect) according to any one of theseventh to tenth aspects, the support end portion includes, along acentral axis of the shaft member, a first shaft portion and a secondshaft portion, the second shaft portion is positioned on the liquid flowpath side with respect to the first shaft portion, and an outer diameterof the second shaft portion is larger than an outer diameter of thefirst shaft portion. With the above configuration, the possibility ofthe elastic member becoming detached from the opening portion can bereduced by inserting the second shaft portion in the opening portion.

In a specific example (a twelfth aspect) according to any one of theseventh to eleventh aspects, the elastic member includes a firstmounting face in which the recessed portion is formed, the shaft memberincludes a second mounting face in which the support end portionprotrudes, and the first mounting face and the second mounting face arein contact with each other. In the above aspect, the first mounting faceof the elastic member and the second mounting face of the shaft membercome in contact with each other. In other words, the first mounting faceand the second mounting face are fixed to each other while opposing eachother with no gap in between. Accordingly, compared with a configurationin which the first mounting face and the second mounting face opposeeach other with a gap in between, the possibility of the elastic memberbecoming detached from the shaft member is reduced.

In a specific example (a thirteenth aspect) of the twelfth aspect, theshaft member includes a groove portion across the second mounting faceand a lateral surface of the support end portion. In the above aspect,the elastic member is pressed from the inside with the gas suppliedthrough the groove portion across the second mounting face and thelateral surface of the support end portion. Accordingly, there is anadvantage in that insertion of the elastic member in the opening portionis facilitated.

In a specific example (a fourteenth aspect) according to any one of thesixth to thirteenth aspects, the shaft member includes a portion that ispositioned outside an outer circumferential edge of the elastic memberwhen viewed in an axial direction of the shaft member. In the aboveaspect, the location and the position of the elastic member can bemaintained in a stable manner by having the portion in the shaft memberthat is positioned outside the outer circumferential edge of the elasticmember contact the inner wall surface of the communication chamber.

In a specific example (a fifteenth aspect) according to any one of thefirst to fourteenth aspects, the communication port is configured tocommunicate with atmospheric air through a communication flow path, andthe communication flow path includes a portion that extends along acentral axis of the opening portion, and a portion that extends in adirection intersecting the central axis. As in the above aspect, in aconfiguration in which the communication flow path that communicates thecommunication chamber with the atmospheric air includes the portion thatextends in the direction intersecting the central axis of the openingportion, it is difficult to insert the elastic member in the openingportion with, for example, a tool. Accordingly, the configuration inwhich the elastic member can be press-fitted in the opening portion withthe gas supplied to the communication chamber through the communicationflow path is especially effective in the present aspect.

The liquid ejecting head according to a specific example (a sixteenthaspect) of any of the first to fifteen aspects further includes a filterthat collects foreign matter mixed in the liquid, in which the liquidflow path is a flow path that supplies the liquid, which passed thefilter, to the nozzle, and the opening portion is a space branched offfrom a point in the liquid flow path between the filter and the nozzle.In the above aspect, by having the cleaning solution flow from thenozzle to the communication chamber through the opening portion, theforeign matter in the vicinity of the nozzle can be discharged to anexternal portion without passing through the filter.

In a specific example (a seventeenth aspect) according to any one of thefirst to sixteenth aspects, a cross-sectional area of the elastic memberis larger than a cross-sectional area of the communication port whenviewed in a direction of a central axis of the opening portion. In theabove aspect, since the cross-sectional area of the elastic member islarger than the cross-sectional area of the communication port, thepossibility of the elastic member passing through the communication portand being discharged to an outside portion is reduced.

In a specific example (an eighteenth aspect) according to any one of thefirst to seventeenth aspects, the elastic member is rubber or elastomer.In a specific example (a nineteenth aspect) according to any one of thefirst to eighteenth aspects, a central axis of the opening portionextends in a vertical direction. In the above aspect, since thedirection in which elastic member is pushed in is the gravitationaldirection, the position of the elastic member before insertion into theopening portion can be easily stabilized.

A liquid ejecting apparatus according to a suitable aspect (a twentiethaspect) includes a liquid ejecting head according to any one of theabove aspects, and a transport mechanism that transports the medium onwhich a liquid is ejected by the liquid ejecting head.

A flow path structure according to a suitable aspect (a twenty-firstaspect) includes a liquid flow path in communication with a nozzle thatejects a liquid, a communication chamber configured to communicate withatmospheric air, a partitioning wall portion provided between the liquidflow path and the communication chamber, the partitioning wall portionincluding an opening portion that communicates the liquid flow path andthe communication chamber to each other, and an elastic member thatcloses the opening portion.

A method of manufacturing a liquid ejecting head according to a suitableaspect (a twenty-second aspect) including a nozzle that ejects a liquid,a liquid flow path in communication with the nozzle, a communicationchamber including a communication port configured to communicate withatmospheric air, a partitioning wall portion provided between the liquidflow path and the communication chamber, the partitioning wall portionincluding an opening portion that communicates the liquid flow path andthe communication chamber to each other, and an elastic memberaccommodated in the communication chamber, the method of manufacturingthe liquid ejecting head including cleaning the nozzle and the liquidflow path by supplying a cleaning solution to the communication chamberthrough the nozzle, the liquid flow path, and the opening portion and bydischarging the cleaning solution through the communication port, andpress-fitting the elastic member in the opening portion by supplying agas to the communication chamber through the communication port.

What is claimed is:
 1. A liquid ejecting head comprising: a nozzleconfigured to eject a liquid; a liquid flow path communicating with thenozzle; a communication chamber including a communication portconfigured to communicate with atmospheric air; a partitioning wallportion provided between the liquid flow path and the communicationchamber, the partitioning wall portion including an opening portion thatcommunicates the liquid flow path and the communication chamber to eachother; and an elastic member closing the opening portion.
 2. The liquidejecting head according to claim 1, wherein the partitioning wallportion includes a first face facing the liquid flow path, and a secondface facing the communication chamber, and a portion of the elasticmember protrudes from the first face towards the liquid flow path. 3.The liquid ejecting head according to claim 1, wherein the elasticmember is press-fitted into the opening portion with a gas suppliedthrough the communication port.
 4. The liquid ejecting head according toclaim 1, wherein the elastic member includes, along a central axis ofthe elastic member, a first portion situated on a liquid flow path side,a second portion situated on a communication chamber side, and a thirdportion situated between the first portion and the second portion, and across-sectional area of the third portion is smaller than across-sectional area of the first portion and a cross-sectional area ofthe second portion.
 5. The liquid ejecting head according to claim 1,wherein an inner circumferential surface of the opening portion includesan inclined surface such that an inner diameter at a first position withrespect to a direction of a central axis of the opening portion issmaller than an inner diameter at a second position with respect to thedirection of the central axis of the opening portion, the secondposition being closer to the communication chamber than is the firstposition.
 6. The liquid ejecting head according to claim 1, furthercomprising: a shaft member having a rigidity that is higher than that ofthe elastic member, wherein the elastic member is provided on the shaftmember.
 7. The liquid ejecting head according to claim 6, wherein theshaft member includes a support end portion situated on a liquid flowpath side, and the elastic member includes a recessed portion that fitsthe support end portion thereto.
 8. The liquid ejecting head accordingto claim 7, wherein an inner diameter of the opening portion is largerthan an outer diameter of the support end portion.
 9. The liquidejecting head according to claim 7, wherein the support end portion isinserted in the opening portion.
 10. The liquid ejecting head accordingto claim 7, wherein a front end of the support end portion is covered bythe elastic member.
 11. The liquid ejecting head according to claim 7,wherein the support end portion includes, along a central axis of theshaft member, a first shaft portion and a second shaft portion, thesecond shaft portion is closer to the liquid flow path than is the firstshaft portion, and an outer diameter of the second shaft portion islarger than an outer diameter of the first shaft portion.
 12. The liquidejecting head according to claim 7, wherein the elastic member includesa first mounting face in which the recessed portion is formed, the shaftmember includes a second mounting face in which the support end portionprotrudes, and the first mounting face and the second mounting face arein contact with each other.
 13. The liquid ejecting head according toclaim 12, wherein the shaft member includes a groove portion across alateral surface of the support end portion and the second mounting face.14. The liquid ejecting head according to claim 6, wherein the shaftmember includes a portion that is positioned outside an outercircumferential edge of the elastic member when viewed in an axialdirection of the shaft member.
 15. The liquid ejecting head according toclaim 1, wherein the communication port is configured to communicatewith atmospheric air through a communication flow path, and thecommunication flow path includes a portion that extends along a centralaxis of the opening portion, and a portion that extends in a directionintersecting the central axis.
 16. The liquid ejecting head according toclaim 1, further comprising: a filter configured to collect foreignmatter mixed in the liquid, wherein the liquid flow path is a flow paththat supplies the liquid, which passed the filter, to the nozzle, andthe opening portion is a space branched off from a point in the liquidflow path between the filter and the nozzle.
 17. The liquid ejectinghead according to claim 1, wherein a cross-sectional area of the elasticmember is larger than a cross-sectional area of the communication portwhen viewed in a direction of a central axis of the opening portion. 18.A liquid ejecting apparatus comprising: a liquid ejecting head accordingto claim 1, the liquid ejecting head ejecting a liquid on a medium; anda transport mechanism that transports the medium.
 19. A flow pathstructure comprising: a liquid flow path communicating with a nozzleconfigured to eject a liquid; a communication chamber configured tocommunicate with atmospheric air; a partitioning wall portion providedbetween the liquid flow path and the communication chamber, thepartitioning wall portion including an opening portion that communicatesthe liquid flow path and the communication chamber to each other; and anelastic member closing the opening portion.
 20. A method ofmanufacturing a liquid ejecting head including a nozzle configured toeject a liquid, a liquid flow path communicating with the nozzle, acommunication chamber including a communication port configured tocommunicate with atmospheric air, a partitioning wall portion providedbetween the liquid flow path and the communication chamber, thepartitioning wall portion including an opening portion that communicatesthe liquid flow path and the communication chamber to each other, and anelastic member accommodated in the communication chamber, the method ofmanufacturing the liquid ejecting head comprising: cleaning the nozzleand the liquid flow path by supplying a cleaning solution to thecommunication chamber through the nozzle, the liquid flow path, and theopening portion and by discharging the cleaning solution through thecommunication port; and press-fitting the elastic member in the openingportion by supplying a gas to the communication chamber through thecommunication port.